Mon, 11 Jun 2018 03:18:22 +0000

Vacuum pump commonly used in vacuum heat treatment furnace

The vacuum pump is the main component of the vacuum heat treatment furnace. Commonly used vacuum pumps are rotary vane vacuum pump, slide valve vacuum pump, roots pump, oil pressure pump, oil diffusion pump and other types.
1. Characteristics and USES of rotary vane vacuum pump
(1) it is used to remove the dry gas in the sealing volume or the gas containing a small amount of condensable vapor. The pneumatic ballast of the pump shall be used in the latter situation.
(2) pre-pumped vacuum pump for oil booster pump, roots pump and oil diffusion pump.
(3) vacuum exhaust for vacuum smelting, vacuum welding, vacuum treatment, vacuum casting, freeze drying, vacuum tube, thermos bottle, etc.
(4) 2 x type vacuum pump can only be used when the environmental temperature 5 ~ 40 ℃.
(5) not suitable for the removal of gases with excessive oxygen content, explosive, corrosive to ferrous metals and chemical reactions to vacuum oil.

 

2. Characteristics and USES of slide valve vacuum pump
This pump USES the strict oil seal device, reliable and durable, the transmission part USES the forced lubrication, the operation is convenient, safe and reliable. The pump can be used to remove gas from the sealed container and a small amount of water vapor or gas containing a small amount of angstrom. Besides using the same range as 2X vacuum pump, it can also be used for vacuum impregnation and true distillation. Most of them are used as the front stage pumps of high real pump. Slide valve pumps are also not suitable for removing gases with high oxygen content, explosive, corrosive to ferrous metals, or chemically reactive to vacuum oil.
Vacuum pump commonly used in vacuum heat treatment furnace

3. Features and USES of roots pump
The roots pump USES two zigzags to rotate in the pump housing to produce suction and exhaust action, with a high compression ratio. It can be used as a booster pump. But it can’t be used alone. It needs to be used in series with the front vacuum pump.
Features:
(1) there are certain gaps between the rotor and the pump cavity, rotor and rotor, which do not contact each other and do not need oil lubrication.
(2) no exhaust valve is required in the pump, and condensable vapor can be removed.
(3) fast start, short time to reach the ultimate vacuum, low power, low operating and maintenance costs.
(4) within a wide range (1x 103 ~ 1pa), there is a large pumping speed. The defect of low pumping speed of diffusion pump and mechanical pump is made up.
Disadvantages:
(1) it is difficult to manufacture pump rotor.
(2) hydrogen extraction is not as effective as oil booster pump.
Roots pump is widely used in vacuum degassing, vacuum smelting, vacuum treatment of molten steel and vacuum heat treatment.
4. Features and USES of oil booster pump
The working pressure range of the oil booster pump is 10 ~ 10-2 Pa, which is between the mechanical pump and the oil diffusion pump. This pump structure is simple, no mechanical part, easy to operate and maintain. Oil booster pump is not suitable for corrosive metal and chemical reaction to pump oil gas.
5. Features and USES of oil diffusion pump
Oil diffusion pump is the main equipment used to obtain high or high vacuum. The working pressure range is 10-2 ~ 10-6pa. Large pumping speed, wide range of pumping speed. Simple structure, no mechanical movement, simple operation, easy maintenance. It is widely used in electronic, metallurgical, chemical and atomic energy industries. Equipped with a cold well device to prevent the return of pump oil.